Want to shop once a month? New techniques can keep meals fresh longer--much longer

In his basement office at the University of Wisconsin, Rich Hartel lines up the failures. The 10-year-old jar of marshmallow crme in which the corn syrup settled into a thick amber pool at the bottom. The two-year-old petrified Peeps. "I have some one-year-old Twinkies at the back of my cabinet," offers Hartel, a professor of food science. Contrary to popular belief that they're immortal, Twinkies are designed for no more than a four-week shelf life, and they tend to become more chewy than soft after the first week. The fact is that most desserts--barring, famously (or infamously), fruitcake--devolve into a sticky...